Mr Brash says he doesn't see why he should learn Te Reo to understand what RNZ is talking about.

"Why should I? Why should I?" he asks. "There are 20-odd radio stations which broadcast in Te Reo, and a Māori TV station."

Mr Brash has previously made scathing statements about Mr Espiner, the "worst offender".

"I'm utterly sick of people talking in Maori on RNZ in what are primarily English-language broadcasts," he said on Facebook.

"The worst offender by some distance is Guyon Espiner on Morning Report, even though he presumably knows that not one listener (to that programme) in hundreds has any knowledge of what he is talking about."

Emma Espiner, who is married to Mr Espiner, hit back at Mr Brash, writing that those complaining about the use of Te Reo probably feel threatened by it.

"These are people who look like them, in spaces which they feel entitled to, doing something that they can't fathom," she said.

"As society shifts, they will continue to yap at our heels and protest, but the trend for Aotearoa is against bland mono-culturalism and fearful mono-lingualism."

However her arguments failed to sway Mr Brash, who continues to be dismissive of the use of Māori in public - saying hardly anyone can understand it.

"It is no value to me, essentially, at all," he says. "It's tokenism of the worst time."